#include <crecipes.p>

#ifndef PRECISION
   #define PRECISION float
   #define HUNT      hunt
#endif

void HUNT(PRECISION xx[], unsigned long n, PRECISION x, unsigned long *jlo)
{
   unsigned long jm,jhi,inc;
   int ascnd;

   ascnd=(xx[n] > xx[1]);
   if (*jlo <= 0 || *jlo > n) {
      *jlo=0;
      jhi=n+1;
   } else {
      inc=1;
      if ((x >= xx[*jlo]) == ascnd) {
         if (*jlo == n) return;
         jhi=(*jlo)+1;
         while ((x >= xx[jhi]) == ascnd) {
            *jlo=jhi;
            inc += inc;
            jhi=(*jlo)+inc;
            if (jhi > n) {
               jhi=n+1;
               break;
            }
         }
      } else {
         if (*jlo == 1) {
            *jlo=0;
            return;
         }
         jhi=(*jlo)--;
         while ((x < xx[*jlo]) == ascnd) {
            jhi=(*jlo);
            inc <<= 1;
            if (inc >= jhi) {
               *jlo=0;
               break;
            }
            else *jlo=jhi-inc;
         }
      }
   }
   while (jhi-(*jlo) != 1) {
      jm=(jhi+(*jlo)) >> 1;
      if ((x > xx[jm]) == ascnd)
         *jlo=jm;
      else
         jhi=jm;
   }
}
/* (C) Copr. 1986-92 Numerical Recipes Software */